THURSDAY, March 12, 2015 (HealthDay News) -- Kidney disease during pregnancy puts women and their babies at risk for certain types of problems, even if the disease is at an early stage and the mother-to-be has normal kidney function, a new study warns.

The risk of pregnancy problems -- such as preterm delivery, high blood pressure in the mother, and the need for neonatal intensive care -- was higher among women with chronic kidney disease. This was true even for those women in the early stages of disease, the investigators reported.

The study was published March 12 in the Journal of the American Society of Nephrology.

"The findings indicate that any kidney disease -- even the least severe, such as a kidney scar from a previous episode of kidney infection, with normal kidney function -- has to be regarded as relevant in pregnancy, and all patients should undergo a particularly careful follow-up," study co-leader Dr. Giorgina Barbara Piccoli, of the University of Torino, said in a news release from the American Society of Nephrology.

"Conversely, we also found that a good outcome was possible in patients with advanced (kidney disease), who are often discouraged to pursue pregnancy," she added.

The findings may prove helpful for prenatal counseling for women with kidney disease and for monitoring them during pregnancy, the researchers said.

In the United States, about 26 million people have chronic kidney disease, they added.